JPH0523435B2 - - Google Patents
Info
- Publication number
- JPH0523435B2 JPH0523435B2 JP59157169A JP15716984A JPH0523435B2 JP H0523435 B2 JPH0523435 B2 JP H0523435B2 JP 59157169 A JP59157169 A JP 59157169A JP 15716984 A JP15716984 A JP 15716984A JP H0523435 B2 JPH0523435 B2 JP H0523435B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- sleeve
- carrier
- developing
- ferrite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910000859 α-Fe Inorganic materials 0.000 claims description 36
- 230000007246 mechanism Effects 0.000 claims description 20
- 230000004907 flux Effects 0.000 claims description 12
- 238000003756 stirring Methods 0.000 claims description 6
- 239000000696 magnetic material Substances 0.000 claims description 4
- 239000002245 particle Substances 0.000 description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- 239000000969 carrier Substances 0.000 description 10
- BGPVFRJUHWVFKM-UHFFFAOYSA-N N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] Chemical compound N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] BGPVFRJUHWVFKM-UHFFFAOYSA-N 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 239000011347 resin Substances 0.000 description 5
- 229910017518 Cu Zn Inorganic materials 0.000 description 3
- 229910017752 Cu-Zn Inorganic materials 0.000 description 3
- 229910017943 Cu—Zn Inorganic materials 0.000 description 3
- 238000004040 coloring Methods 0.000 description 3
- 229910001035 Soft ferrite Inorganic materials 0.000 description 2
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 210000005069 ears Anatomy 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- 238000007790 scraping Methods 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- DHKHKXVYLBGOIT-UHFFFAOYSA-N 1,1-Diethoxyethane Chemical compound CCOC(C)OCC DHKHKXVYLBGOIT-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 238000005766 Middleton reaction Methods 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- AUNAPVYQLLNFOI-UHFFFAOYSA-L [Pb++].[Pb++].[Pb++].[O-]S([O-])(=O)=O.[O-][Cr]([O-])(=O)=O.[O-][Mo]([O-])(=O)=O Chemical compound [Pb++].[Pb++].[Pb++].[O-]S([O-])(=O)=O.[O-][Cr]([O-])(=O)=O.[O-][Mo]([O-])(=O)=O AUNAPVYQLLNFOI-UHFFFAOYSA-L 0.000 description 1
- 239000011354 acetal resin Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- CJOBVZJTOIVNNF-UHFFFAOYSA-N cadmium sulfide Chemical compound [Cd]=S CJOBVZJTOIVNNF-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- XCJYREBRNVKWGJ-UHFFFAOYSA-N copper(II) phthalocyanine Chemical compound [Cu+2].C12=CC=CC=C2C(N=C2[N-]C(C3=CC=CC=C32)=N2)=NC1=NC([C]1C=CC=CC1=1)=NC=1N=C1[C]3C=CC=CC3=C2[N-]1 XCJYREBRNVKWGJ-UHFFFAOYSA-N 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- PLYDMIIYRWUYBP-UHFFFAOYSA-N ethyl 4-[[2-chloro-4-[3-chloro-4-[(3-ethoxycarbonyl-5-oxo-1-phenyl-4h-pyrazol-4-yl)diazenyl]phenyl]phenyl]diazenyl]-5-oxo-1-phenyl-4h-pyrazole-3-carboxylate Chemical compound CCOC(=O)C1=NN(C=2C=CC=CC=2)C(=O)C1N=NC(C(=C1)Cl)=CC=C1C(C=C1Cl)=CC=C1N=NC(C(=N1)C(=O)OCC)C(=O)N1C1=CC=CC=C1 PLYDMIIYRWUYBP-UHFFFAOYSA-N 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- VENDXQNWODZJGB-UHFFFAOYSA-N n-(4-amino-5-methoxy-2-methylphenyl)benzamide Chemical compound C1=C(N)C(OC)=CC(NC(=O)C=2C=CC=CC=2)=C1C VENDXQNWODZJGB-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920006324 polyoxymethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
- G03G15/0921—Details concerning the magnetic brush roller structure, e.g. magnet configuration
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G13/00—Electrographic processes using a charge pattern
- G03G13/06—Developing
- G03G13/08—Developing using a solid developer, e.g. powder developer
- G03G13/09—Developing using a solid developer, e.g. powder developer using magnetic brush
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Magnetic Brush Developing In Electrophotography (AREA)
Description
発明の分野
本発明は、電子写真法における現像装置に関す
るもので、より詳細にはフエライトキヤリヤと顕
電性トナーとから成る二成分系現像剤を用いて、
静電像の現像を行う装置に関するものである。
従来の技術及び発明の技術的課題
二成分系磁性現像剤を用いる電子写真法におい
ては、顕電性トナーと磁性キヤリヤとを混合し、
この二成分系組成物を、内部に磁石を備えた現像
スリーブ上に供給して、この組成物から成る磁気
ブラシを形成させ、静電潜像を有する電子写真感
光板にこの磁気ブラシを摺擦せしめることによ
り、顕電性トナー像を感光板上に形成させる。顕
電性トナーは磁性キヤリヤとの摩擦により、感光
板上の静電潜像の電荷とは逆極性の電荷に帯電さ
れ、磁気ブラシ上の顕電性トナー粒子がクーロン
力により静電潜像上に付着して、静電潜像の現像
が行われる。一方磁性キヤリヤはスリーブ内の磁
石により吸引されており、しかもその帯電電荷が
静電潜像の電荷と同極性であり、そのため、磁性
キヤリヤはスリーブ上にそのまま残ることにな
る。
磁性キヤリヤとしては一般に、鉄粉キヤリヤが
広く使用されているが、この鉄粉キヤリヤには未
だ多くの欠点が認められる。即ち、この鉄粉キヤ
リヤを用いた二成分系現像剤では、現像感度曲線
（静電像と現像スリーブ間の電位差対画像濃度の
曲線）の立上りが急で、階調性に劣り、中間調の
再現性に乏しいという欠点がある。また、この鉄
粉キヤリヤを含む現像剤は硬い磁気ブラシを形成
することがあり、感光層を傷つける可能性がある
と共に、ベタ黒部の複写に際しては、形成される
画像に、ブラシマーク、即ちブラシの摺擦方向に
延びている細くて短い白線の多数の列が入るとい
う欠点が認められる。更に、鉄粉キヤリヤは湿度
に敏感であり、湿度の影響により現像特性が変化
したり、或いはそれ自体錆を発生する傾向があ
る。
これらの欠点を解消するものとして、近年フエ
ライト、特にソフトフエライトを磁性キヤリヤと
して用いることが提案されている。しかしなが
ら、フエライトキヤリヤは、粒子としての特性や
磁気的特性が鉄粉キヤリヤと著しく異なるため、
鉄粉キヤリヤを用いる場合の現像条件をそのまま
用いることはできない。例えば、鉄粉キヤリヤは
粒子形状が不定形であるのに対して、フエライト
キヤリヤはほぼ球状であり、またフエライトキヤ
リヤは鉄粉キヤリヤに比して小さい透磁性を有す
る。このため、フエライトキヤリヤを用いた二成
分系磁性現像剤では、鉄粉キヤリヤを使用したも
のに比して、磁気ブラシの穂立が小さく、磁気ブ
ラシの穂長をかなり短かくしなければ、良好な画
質のトナー像が得られないという問題がある。ま
た、フエライトキヤリヤを用いた二成分系磁性現
像剤の穂切をこのように短かくすると、現像スリ
ーブの回転に過度のトルクを必要とするようにな
り、これにより現像装置のブレや振動を生じて、
現像を良好に行えないとか、或いは光学系にもブ
レを生ずるという欠点を生ずる。
発明の目的
従つて、本発明の目的は、上述した欠点が解消
された、フエライトキヤリヤ用の現像装置を提供
するにある。
本発明の他の目的は、現像域では二成分系現像
剤の磁気ブラシの穂立が良好に行われると共に、
磁気ブラシの搬送、穂切が小さいトルクで円滑に
行われるフエライトキヤリヤ用の現像装置を提供
するにある。
発明の構成
本発明によれば、非磁性材料から成る現像用ス
リーブ、該スリーブ内に固定された複数個の磁極
を備えた磁石、該スリーブを回転駆動するための
機構、磁性キヤリヤと顕電性トナーとから成る現
像剤を撹拌してスリーブに供給する機構、スリー
ブ上に形成される磁気ブラシを所定の穂長に穂切
して現像域に供給する機構、現像域を通過した磁
気ブラシをスリーブから掻落す機構から成り、前
記磁極は現像域に対応する現像用主極と現像剤の
供給位置から穂切位置迄の搬送域に対応する搬送
用磁極とから成る現像装置であつて、
前記磁性キヤリヤがフエライトキヤリヤであ
り、前記穂切機構による磁気ブラシの穂切長が
0.8乃至1.2mmに設定され、
搬送用磁極が現像用主極の50乃至85％の磁束密
度を有することを特徴とする現像装置が提供され
る。
発明の好適態様
本発明を、添付図面を参照しつつ以下に詳細に
説明する。
本発明の現像装置の全体の配置を、感光層と共
に示す第１図において、例えば矢印Ａ方向に駆動
されるドラム１の表面には、セレン系光導電体層
のような電子写真感光層２が設けられており、そ
の表面には、図示していないが、一様帯電及び画
像露光のような手段で静電潜像が形成される。
この感光層２の移動路に沿つて全体として３で
示す現像装置が設けられる。この装置内には、複
数の磁極を備えたマグネツト４があり、このマグ
ネツト４の周囲には、アルミの如き非磁性材料か
ら成るスリーブ５が設けられている。このスリー
ブ５は、矢印Ｂ方向に回転可能に設けられてお
り、このスリーブ５内にマグネツト４は固定され
て設けられている。二成分系現像剤６を撹拌する
ために、撹拌機構７が設けられており、この撹拌
機構７により、フエライトキヤリヤと顕電性トナ
ー粒子とは混合されて、相互に摩擦帯電して、相
互に静電的に結合した混合物が形成され、スリー
ブ５上に供給される。
二成分系現像剤は、スリーブ５上で磁気ブラシ
８を形成し、この磁気ブラシは穂切機構９により
適当な穂長に切揃えられて、現像域１０に供給さ
れる。現像域１０において、感光層２とスリーブ
５とは互いに逆方向に移動し、磁気ブラシ８と感
光層２との摺擦が行われる。摺擦により、フエラ
イトキヤリヤ上の帯電トナー粒子は感光層２の静
電潜像に吸引され、静電潜像の現像が行われる。
現像後の磁気ブラシは、掻落し板１１によりスリ
ーブ５から剥離され、剥離された二成分系現像剤
は、撹拌機構７により撹拌された後、再びスリー
ブ５上に供給される。現像で消費されるトナー１
２を供給するために、トナー収容部１３とトナー
補給ローラ１４とが設けられ、現像機構３内にト
ナー１２を連続的或いは間欠的に供給する。
尚、スリーブ５の一端部には、図示していない
がスプロケツトの如き駆動機構が設けられてお
り、駆動モータ及びチエーン（共に図示せず）に
より矢印Ｂ方向に駆動されるよりになつている。
本発明においては、キヤリヤとしてフエライト
キヤリヤを使用していることに関連して穂切機構
９とスリーブ５とのクリアランス、即ち磁気ブラ
シの穂切長は、0.8乃至1.2mmの範囲に設定され
る。この穂切長は、鉄粉キヤリヤを用いる場合の
穂切長が一般に2.5乃至3.5mmの範囲にあるのに比
してもかなり短いものであることが了解されよ
う。
現像スリーブ５の内部には、複数の磁極を備え
た磁石４が設けられているが、この磁極は、現像
域１０に対応して、感光層２とほぼ対向する位置
関係で設けられた現像用主極１５、現像剤の供給
位置１６から穂切機構９に至る搬送域に対応する
搬送用磁極１７，１８とから成つている。第１図
に示す具体例において、磁極１７は現像剤のスリ
ーブ５への汲上げ用の機能をも備えており、一方
磁極１８は、穂切時に磁気ブラシの穂を立てる作
用をも有している。
本発明において、二成分系現像剤の磁性キヤリ
ヤとしてフエライトキヤリヤを用いることに関連
して、搬送用磁極１７，１８として、現像用主極
１５の磁束密度（H1）の50乃至85％、特に55乃
至80％の磁束密度（H2）を有するものを使用す
る。
第２図は、搬送用磁極１７，１８の磁束密度
（H2）を変化させ、H2／H1×100（％）の値を横
軸とし、スリーブ５の回転に必要なトルク（Kg・
cm）を右側の縦軸、及び形成されるトナー像の画
像濃度を左側の縦軸とし、得られた実験値をプロ
ツトしたものであり、図中白丸（○）はトルクの
値、黒丸（●）は画像濃度の値を示すものであ
る。
この第２図の結果から、搬送用磁極１７，１８
の磁束密度（H2）を主極１５の磁束密度（H1）
の85％以下とすることが、スリーブの駆動トルク
を、現像装置のブレや振動を実質上生じない8.5
Kg・cm以下のレベルに抑制する上で臨界的である
ことが了解される。また、搬送用磁極１７，１８
の磁束密度（H2）を主極１５の磁束密度（H1）
の50％以上とすることが、現像剤磁気ブラシの搬
送速度を現像に不足しないものとして、十分な画
像濃度を得る上で極めてクリテカルであることが
了解される。しかも、本発明によれば、搬送用磁
極１７，１８に比して現像用主極１５の磁束密度
（H1）を高めることにより、静電像の現像に必要
な十分な穂立ちが確保されるという利点も達成さ
れる。
本発明において、現像用主極１５の磁束密度
（H1）は、一般に800乃至1000ガウスの範囲内に
あれば満足すべき結果が得られ、一方搬送用磁極
１７，１８の磁束密度（H2）は前述した条件が
満足されるように定められる。
本発明において、フエライトキヤリヤとして
は、それ自体公知の任意のフエライトキヤリヤ、
特に焼結フエライト粒子が使用される。フエライ
ト焼結粒子はそれ自体公知のものであり、公知の
焼結フエライト粒子、特に球状の焼結フエライト
粒子が有利に使用される。フエライトの組成も公
知のものであり、一般にソフトフエライトと呼ば
れるもの、例えばこれに限定されるものでない
が、Zn系フエライト、Ni系フエライト、Cu系フ
エライト、Mn系フエライト、Mn−Zn系フエラ
イト、Mn−Mg系フエライト、Cu−Zn系フエラ
イト、Ni−Zn系フエライト、Mn−Cu−Zn系フ
エライト等が挙げられる。好適なフエライトは、
原子重量％で、Fe35乃至65％、Cu5乃至15％、
Zn5乃至15％及びMn0乃至0.5％から成るCu−Zn
系又はCu−Zn−Mn系フエライトである。
用いる焼結フエライト粒子は、一般に平均粒径
が30乃至100ミクロン、特に35乃至45ミクロンに
あるものが望ましい。
用いる顕電性トナーは、顕電性と共に着色性、
定着性を具備するものであり、定着用樹脂媒質、
着色用顔料及び電荷制御染料を必須成分として含
有する。
定着用樹脂としては、熱可塑性樹脂や、未硬化
乃至は初期縮合物の熱硬化性樹脂が使用される。
その適当な例は、重要なものの順序に、ポリスチ
レン等のビニール芳香族樹脂、アクリル系樹脂、
ポリビニルアセタール樹脂、ポリエステル樹脂、
エポキシ樹脂、フエノール樹脂、石油樹脂、オレ
フイン樹脂等である。着色用顔料としては例えば
カーボンブラツク、カドミウムエロー、モリブデ
ンオレンジ、ピラゾロンレツド、フアストバイオ
レツトＢ、フタロシアニンブルー等の１種又は２
種以上が使用される。
トナー粒子の平均粒径は一般に９乃至15μ、特
に10乃至13μのものが好適である。
フエライトキヤリヤとトナーとは100：５乃至
100：14の重量比で混合し、本発明の現像装置に
用いる。
本発明を以下の例で更に説明する。
実施例
第１図に示す現像装置の磁石４の現像主極１５
をN1、搬送用磁極１７をN2、および１８をS1と
してこれらの磁極の磁石強度の異なる５種の磁石
ロールを用意した。（第１表）
FIELD OF THE INVENTION The present invention relates to a developing device for electrophotography, and more particularly, it uses a two-component developer consisting of a ferrite carrier and a electrostatic toner.
The present invention relates to an apparatus for developing an electrostatic image. Prior Art and Technical Problems of the Invention In electrophotography using a two-component magnetic developer, electrostatic toner and magnetic carrier are mixed,
This two-component composition is supplied onto a developing sleeve equipped with a magnet inside to form a magnetic brush made of this composition, and this magnetic brush is rubbed against an electrophotographic photosensitive plate having an electrostatic latent image. By this, an electrostatic toner image is formed on the photosensitive plate. Due to friction with the magnetic carrier, the electrostatic toner is charged to a charge of opposite polarity to that of the electrostatic latent image on the photosensitive plate, and electrostatic toner particles on the magnetic brush are transferred onto the electrostatic latent image by Coulomb force. The electrostatic latent image is developed. On the other hand, the magnetic carrier is attracted by the magnet in the sleeve, and its electric charge is of the same polarity as the charge of the electrostatic latent image, so that the magnetic carrier remains on the sleeve. Generally, iron powder carriers are widely used as magnetic carriers, but these iron powder carriers still have many drawbacks. In other words, in a two-component developer using this iron powder carrier, the development sensitivity curve (curve of potential difference between the electrostatic image and the developing sleeve versus image density) rises steeply, the gradation is poor, and the middle tones are poor. It has the disadvantage of poor reproducibility. In addition, the developer containing this iron powder carrier may form a hard magnetic brush, which may damage the photosensitive layer, and when copying a solid black area, a brush mark, that is, a brush mark, may be formed on the image formed. The disadvantage is that there are many rows of thin and short white lines extending in the rubbing direction. Furthermore, iron powder carriers are sensitive to humidity and tend to change development characteristics or to rust themselves. In order to overcome these drawbacks, it has recently been proposed to use ferrite, especially soft ferrite, as a magnetic carrier. However, ferrite carriers have significantly different particle characteristics and magnetic properties than iron powder carriers, so
The development conditions when using an iron powder carrier cannot be used as they are. For example, iron powder carriers have irregular particle shapes, whereas ferrite carriers have approximately spherical shapes, and ferrite carriers have lower magnetic permeability than iron powder carriers. For this reason, in a two-component magnetic developer using a ferrite carrier, the spikes of the magnetic brush are smaller than those using an iron powder carrier, and unless the length of the magnetic brush is significantly shortened, it will not work properly. There is a problem in that a toner image of high quality cannot be obtained. Furthermore, if the spikes of a two-component magnetic developer using a ferrite carrier are shortened in this way, excessive torque is required to rotate the developing sleeve, which reduces shaking and vibration of the developing device. arise,
This results in drawbacks such as not being able to perform development well or causing blurring in the optical system. OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a developing device for a ferrite carrier in which the above-mentioned drawbacks are eliminated. Another object of the present invention is to allow the magnetic brush of the two-component developer to stand up well in the developing area, and to
To provide a developing device for a ferrite carrier in which conveyance of a magnetic brush and cutting of ears can be carried out smoothly with small torque. According to the present invention, there is provided a developing sleeve made of a non-magnetic material, a magnet having a plurality of magnetic poles fixed in the sleeve, a mechanism for rotationally driving the sleeve, a magnetic carrier, and an electrostatic magnet. A mechanism that stirs the developer consisting of toner and supplies it to the sleeve, a mechanism that cuts the magnetic brush formed on the sleeve into a predetermined length and supplies it to the development area, and a mechanism that supplies the magnetic brush that has passed through the development area to the sleeve. The developing device comprises a mechanism for scraping off the magnetic material, and the magnetic pole is composed of a main developing pole corresponding to the developing area and a conveying magnetic pole corresponding to the conveying area from the developer supply position to the ear cutting position, The carrier is a ferrite carrier, and the ear cutting length of the magnetic brush by the ear cutting mechanism is
There is provided a developing device characterized in that the magnetic flux density is set to 0.8 to 1.2 mm, and the conveying magnetic pole has a magnetic flux density of 50 to 85% of that of the main developing pole. PREFERRED EMBODIMENTS OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. In FIG. 1, which shows the overall arrangement of the developing device of the present invention together with photosensitive layers, an electrophotographic photosensitive layer 2 such as a selenium-based photoconductor layer is formed on the surface of a drum 1 driven in the direction of arrow A, for example. Although not shown, an electrostatic latent image is formed on the surface thereof by means such as uniform charging and image exposure. A developing device, generally designated by 3, is provided along the path of movement of the photosensitive layer 2. This device includes a magnet 4 having a plurality of magnetic poles, and around the magnet 4 is provided a sleeve 5 made of a non-magnetic material such as aluminum. This sleeve 5 is provided so as to be rotatable in the direction of arrow B, and the magnet 4 is fixedly provided within this sleeve 5. A stirring mechanism 7 is provided to stir the two-component developer 6, and the stirring mechanism 7 mixes the ferrite carrier and the electrostatic toner particles, and frictionally charges each other. A mixture is formed which is electrostatically bonded to and applied onto the sleeve 5. The two-component developer forms a magnetic brush 8 on the sleeve 5, and this magnetic brush is cut to a suitable length by a cutting mechanism 9 and supplied to a developing area 10. In the development area 10, the photosensitive layer 2 and the sleeve 5 move in opposite directions, and the magnetic brush 8 and the photosensitive layer 2 are rubbed against each other. By rubbing, the charged toner particles on the ferrite carrier are attracted to the electrostatic latent image on the photosensitive layer 2, and the electrostatic latent image is developed.
After development, the magnetic brush is peeled off from the sleeve 5 by the scraping plate 11, and the peeled two-component developer is stirred by the stirring mechanism 7 and then supplied onto the sleeve 5 again. Toner consumed during development 1
In order to supply the toner 12, a toner storage section 13 and a toner supply roller 14 are provided, and the toner 12 is continuously or intermittently supplied into the developing mechanism 3. A drive mechanism such as a sprocket (not shown) is provided at one end of the sleeve 5, and is driven in the direction of arrow B by a drive motor and chain (both not shown). In the present invention, since a ferrite carrier is used as a carrier, the clearance between the ear cutting mechanism 9 and the sleeve 5, that is, the ear cutting length of the magnetic brush is set in the range of 0.8 to 1.2 mm. . It will be appreciated that this cutting length is considerably shorter than the cutting length when using an iron powder carrier, which is generally in the range of 2.5 to 3.5 mm. A magnet 4 having a plurality of magnetic poles is provided inside the developing sleeve 5, and these magnetic poles correspond to the developing area 10 and are provided in a position substantially facing the photosensitive layer 2 for development. It consists of a main pole 15 and conveyance magnetic poles 17 and 18 corresponding to the conveyance area from the developer supply position 16 to the ear cutting mechanism 9. In the specific example shown in FIG. 1, the magnetic pole 17 also has the function of pumping up the developer into the sleeve 5, while the magnetic pole 18 also has the function of raising the ears of the magnetic brush during ear cutting. There is. In the present invention, in connection with using a ferrite carrier as a magnetic carrier for a two-component developer, the magnetic flux density (H 1 ) of the main pole for development 15 is 50 to 85% as the magnetic poles for conveyance 17 and 18; In particular, one having a magnetic flux density (H 2 ) of 55 to 80% is used. FIG . 2 shows the torque (Kg・
cm) on the right vertical axis, and the image density of the toner image formed on the left vertical axis. ) indicates the image density value. From the results shown in FIG.
The magnetic flux density (H 2 ) of the main pole 15 (H 1 )
By setting the sleeve drive torque to 85% or less of the 8.5
It is understood that it is critical to suppress it to a level below Kg/cm. In addition, the conveying magnetic poles 17, 18
The magnetic flux density (H 2 ) of the main pole 15 (H 1 )
It is understood that setting the developer magnetic brush to 50% or more is extremely critical in order to ensure that the conveyance speed of the developer magnetic brush is not insufficient for development and to obtain sufficient image density. Furthermore, according to the present invention, by increasing the magnetic flux density (H 1 ) of the main developing pole 15 compared to the conveying magnetic poles 17 and 18, sufficient spike formation necessary for developing an electrostatic image is ensured. The advantage of being more efficient is also achieved. In the present invention, satisfactory results can be obtained if the magnetic flux density (H 1 ) of the main developing pole 15 is generally within the range of 800 to 1000 Gauss, while the magnetic flux density (H 2 ) of the conveying magnetic poles 17 and 18 ) is determined so that the above-mentioned conditions are satisfied. In the present invention, the ferrite carrier may be any per se known ferrite carrier,
In particular, sintered ferrite particles are used. Sintered ferrite particles are known per se, and known sintered ferrite particles, in particular spherical sintered ferrite particles, are advantageously used. The composition of ferrite is also known, and includes what is generally called soft ferrite, such as, but not limited to, Zn-based ferrite, Ni-based ferrite, Cu-based ferrite, Mn-based ferrite, Mn-Zn-based ferrite, and Mn-based ferrite. Examples include -Mg ferrite, Cu-Zn ferrite, Ni-Zn ferrite, Mn-Cu-Zn ferrite, and the like. A suitable ferrite is
In atomic weight%, Fe35 to 65%, Cu5 to 15%,
Cu-Zn consisting of 5-15% Zn and 0-0.5% Mn
or Cu-Zn-Mn type ferrite. The sintered ferrite particles used generally have an average particle size of 30 to 100 microns, preferably 35 to 45 microns. The electrostatic toner used has electrostatic property, coloring property,
It has fixing properties, and includes a fixing resin medium,
Contains coloring pigments and charge control dyes as essential ingredients. As the fixing resin, a thermoplastic resin or an uncured or initial condensate thermosetting resin is used.
Suitable examples include, in order of importance, vinyl aromatic resins such as polystyrene, acrylic resins,
Polyvinyl acetal resin, polyester resin,
These include epoxy resins, phenolic resins, petroleum resins, and olefin resins. Examples of coloring pigments include one or two of carbon black, cadmium yellow, molybdenum orange, pyrazolone red, fast violet B, phthalocyanine blue, etc.
More than one species is used. The average particle size of the toner particles is generally 9 to 15 microns, particularly preferably 10 to 13 microns. Ferrite carrier and toner are 100:5 to 100:5.
They are mixed at a weight ratio of 100:14 and used in the developing device of the present invention. The invention is further illustrated by the following examples. Embodiment Main developing pole 15 of magnet 4 of the developing device shown in FIG.
Five types of magnet rolls were prepared, in which the magnetic pole 17 was N 1 , the conveying magnetic pole 17 was N 2 , and the magnetic pole 18 was S 1 with different magnetic strengths. (Table 1)
【表】
第１表に磁石をそれぞれ第１図の現像装置に装
着し、その時の現像用スリーブにかかるトルク、
および画像品質を観察した。なお、この時の二成
分系現像剤、および、現像条件は次の通りであ
る。
（二成分系現像剤）
Γキヤリアフエライトキヤリア
飽和磁化 60emu／ｇ
残留磁化 0.3emn／ｇ
保磁力 3O¨e
平均粒径 45μ
Γトナー 平均粒径 12μ
Γ混合比 キヤリヤ：トナー＝100：11
（現像条件）
・ドラム−スリーブ間 1.6mm
・周速比（Ｓ／Ｄ） 1.8（但し、スリーブ速度
160mm／Ｓ）
・穂切長 1.0mm
結果を次の第２表に示す。[Table] Table 1 shows the torque applied to the developing sleeve when each magnet is attached to the developing device shown in Figure 1.
and image quality were observed. Note that the two-component developer and development conditions at this time are as follows. (Two-component developer) Γ carrier Felite carrier
Saturation magnetization 60emu/g Residual magnetization 0.3emn/g Coercive force 3O¨e Average particle size 45μ Γ toner Average particle size 12μ Γ mixture ratio Carrier: toner = 100:11 (Development conditions) ・Drum-sleeve distance 1.6mm ・Peripheral speed Ratio (S/D) 1.8 (However, sleeve speed
160mm/S) - Panicle cut length 1.0mm The results are shown in Table 2 below.
第１図は本発明の現像装置の構成を示す概略
図、第２図は搬送用磁極の現像主極に対する磁束
密度の割合とスリーブのトルク及び画像濃度の関
係を示したグラフ図である。
図中、２は感光層、３は現像装置、４はマグネ
ツト、５はスリーブ、６は二成分系現像剤、１５
は現像用主極、１７，１８は搬送用磁極である。
FIG. 1 is a schematic diagram showing the structure of the developing device of the present invention, and FIG. 2 is a graph diagram showing the relationship between the ratio of the magnetic flux density of the conveying magnetic pole to the main developing pole, the torque of the sleeve, and the image density. In the figure, 2 is a photosensitive layer, 3 is a developing device, 4 is a magnet, 5 is a sleeve, 6 is a two-component developer, 15
is a main pole for development, and 17 and 18 are magnetic poles for conveyance.
Claims (1)
ーブ内に固定された複数個の磁極を備えた磁石、
該スリーブを回転駆動するための機構、磁性キヤ
リヤと顕電性トナーとから成る現像剤を撹拌して
スリーブに供給する機構、スリーブ上に形成され
る磁気ブラシを所定の穂長に穂切して現像域に供
給する機構、現像域を通過した磁気ブラシをスリ
ーブから掻落す機構から成り、前記磁極は、現像
域に対応する現像用主極と現像剤の供給位置から
穂切位置迄の搬送域に対応する搬送用磁極とから
成る現像装置であつて、 前記磁性キヤリヤがフエライトキヤリヤであ
り、 前記穂切機構による磁気ブラシの穂切長が0.8
乃至1.2mmに設定され、 搬送用磁極が現像用主極の50乃至85％の磁束密
度を有することを特徴とする現像装置。[Claims] 1. A developing sleeve made of a non-magnetic material, a magnet having a plurality of magnetic poles fixed within the sleeve,
A mechanism for rotationally driving the sleeve, a mechanism for stirring and supplying the developer consisting of a magnetic carrier and electrostatic toner, and a mechanism for cutting the magnetic brush formed on the sleeve into a predetermined length. It consists of a mechanism that supplies the magnetic brush to the developing area, and a mechanism that scrapes off the magnetic brush that has passed through the developing area from the sleeve. and a conveying magnetic pole corresponding to the magnetic carrier, wherein the magnetic carrier is a ferrite carrier, and the ear cutting length of the magnetic brush by the ear cutting mechanism is 0.8.
A developing device characterized in that the magnetic flux density is set to 1.2 mm to 1.2 mm, and the transport magnetic pole has a magnetic flux density of 50 to 85% of that of the main developing pole.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15716984A JPS6136774A (en) | 1984-07-30 | 1984-07-30 | Developing device |
| US06/760,587 US4686935A (en) | 1984-07-30 | 1985-07-30 | Developing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15716984A JPS6136774A (en) | 1984-07-30 | 1984-07-30 | Developing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6136774A JPS6136774A (en) | 1986-02-21 |
| JPH0523435B2 true JPH0523435B2 (en) | 1993-04-02 |
Family
ID=15643693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15716984A Granted JPS6136774A (en) | 1984-07-30 | 1984-07-30 | Developing device |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4686935A (en) |
| JP (1) | JPS6136774A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4873551A (en) * | 1987-03-16 | 1989-10-10 | Canon Kabushiki Kaisha | Developing apparatus using magnetic carrier under AC field |
| JP2556506B2 (en) * | 1987-03-16 | 1996-11-20 | キヤノン株式会社 | Development device |
| JP2505800B2 (en) * | 1987-03-16 | 1996-06-12 | キヤノン株式会社 | Development device |
| DE69028931T2 (en) * | 1989-04-28 | 1997-02-13 | Mita Industrial Co Ltd | Development process with excellent image reproduction |
| JP3914755B2 (en) * | 2001-11-27 | 2007-05-16 | 株式会社リコー | Developing device and image forming apparatus |
| JP3930873B2 (en) * | 2004-06-18 | 2007-06-13 | シャープ株式会社 | Two-component developer and two-component developing apparatus using the same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55133069A (en) * | 1979-04-03 | 1980-10-16 | Matsushita Electric Ind Co Ltd | Magnetic brush developing device |
| JPS59210468A (en) * | 1983-05-13 | 1984-11-29 | Toshiba Corp | Developing device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4976630U (en) * | 1972-10-20 | 1974-07-03 | ||
| GB2105222B (en) * | 1981-07-10 | 1985-08-07 | Konishiroku Photo Ind | Developing apparatus |
| US4451134A (en) * | 1981-12-18 | 1984-05-29 | Konishiroku Photo Industry Co., Ltd. | Magnetic-brush developing device |
| US4557992A (en) * | 1984-03-26 | 1985-12-10 | Konishiroku Photo Industry Co., Ltd. | Developing method |
-
1984
- 1984-07-30 JP JP15716984A patent/JPS6136774A/en active Granted
-
1985
- 1985-07-30 US US06/760,587 patent/US4686935A/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55133069A (en) * | 1979-04-03 | 1980-10-16 | Matsushita Electric Ind Co Ltd | Magnetic brush developing device |
| JPS59210468A (en) * | 1983-05-13 | 1984-11-29 | Toshiba Corp | Developing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6136774A (en) | 1986-02-21 |
| US4686935A (en) | 1987-08-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH03251882A (en) | Developing device | |
| EP0183509B2 (en) | Magnetic brush developing method | |
| JP2923334B2 (en) | Development method | |
| JPS6087349A (en) | Toner coating method | |
| JPH0523435B2 (en) | ||
| JPS5994763A (en) | Two-component type developer for magnetic brush developing | |
| JPS6129856A (en) | Electrostatic latent image developing method | |
| JPH07140725A (en) | Triboelectric charge imparting member for negative charge type toner | |
| JPS61166558A (en) | Image forming device | |
| JPH053588B2 (en) | ||
| JPS60123859A (en) | Developing method | |
| JPS603675A (en) | Electrostatic charge image developing device | |
| EP0405686B1 (en) | Developing process for forming image having high quality | |
| JPS6018068B2 (en) | Magnetic brush development and cleaning method | |
| JPS59223452A (en) | Composition for developer | |
| JPS6165262A (en) | Image forming method | |
| JP3009436B2 (en) | Development method | |
| JPH0414056A (en) | Developing method | |
| JP3047073B2 (en) | High density development method | |
| JPS63225269A (en) | Developing device | |
| JPS61174556A (en) | Image forming method | |
| JPH0237366A (en) | Carrier for binary developer | |
| JPH0680465B2 (en) | Magnetic brush development method | |
| JPS5921028B2 (en) | Electrostatic latent image development method | |
| JPH1048959A (en) | Image forming device |